101 questions from 13 interviews · updated from reports 2016-2024
About
FICO is an analytics software company known for credit scoring, decision management, and tools used by lenders, insurers, and other businesses to assess risk. In India, it hires technical talent for Software Engineer, SDE, and Solution Engineer roles across product development, integrations, and customer implementations.
The roles that come up most are Software Engineer, Solution Engineer and SDE. This covers 13 candidate interviews reported from 2016 to 2024. Most sat it at entry level (10 of 13 that recorded a level), with 3 internship interviews alongside. Among the 11 that recorded either route, arrivals split between campus drives (11, 100%). Most questions fall under CS fundamentals and DSA.
Ans. An abstract class is a partial base class, while an interface is mainly a contract a class agrees to implement. An abstract class can hold instance state, constructors, and concrete methods, but a class can extend only one. A class can implement multiple interfaces, which is useful for defining shared capabilities.
Ans. SQL joins combine rows from two tables using a related column or condition. An inner join returns only matching rows. A left join returns all rows from the left table plus matches from the right. A right join does the reverse. A full outer join returns all rows from both sides. A cross join returns every combination.
Ans. Traverse the tree level by level and record the first node seen at each level. Use a queue for breadth-first search, process nodes level by level, and add the first node of each level to the result. This gives the left view in O(n) time and O(w) space, where w is maximum width.
Ans. Trees are hierarchical data structures with a root and parent-child relationships, while graphs are more general structures made of vertices connected by edges. A tree is a connected acyclic graph. Graphs may be directed, undirected, weighted, or cyclic. Common operations use DFS or BFS, with adjacency lists often giving efficient space and traversal time.
Ans. Deletion in a Binary Search Tree removes a node while preserving the ordering property. First search for the key, then handle three cases: leaf node, node with one child, or node with two children. The key detail is replacing a two-child node with its inorder successor or predecessor. Time complexity is O(h).
Ans. A DBMS is software that stores, organises and retrieves data while enforcing rules for correctness and access. The key fundamentals are schemas, tables, keys, relationships, SQL, indexing, normalisation, transactions and concurrency control. The most important detail is ACID transactions, which keep data consistent even with failures or simultaneous users.
Ans. Virtual memory is an operating system technique that gives each process its own logical address space, mapped to physical RAM by the memory management unit. The key detail is paging: memory is split into pages, and pages not currently in RAM can be stored on disk, enabling isolation, protection, and efficient memory use.
Ans. Spring MVC is a Java web framework in the Spring ecosystem that implements the Model View Controller pattern for building web applications. Its main components are DispatcherServlet, controllers, models, views, view resolvers, and handler mappings. DispatcherServlet is the front controller that routes requests, calls controllers, and returns the chosen view with data.
Ans. A binary tree is a tree where each node has at most two children, usually called left and right. A binary search tree is a binary tree with an ordering rule: values in the left subtree are smaller, and values in the right subtree are larger. This makes search, insert, and delete O(h).
Ans. Database normalization is the process of organising relational database tables to reduce duplication and avoid update, insert, and delete anomalies. The main forms are 1NF, which removes repeating groups; 2NF, which removes partial dependency; 3NF, which removes transitive dependency; and BCNF, which enforces stricter dependency rules.
Ans. Build an event driven medal tally service where official result events create immutable medal award records, and materialised views maintain country totals. Ingest results from the Games authority, validate idempotently, publish to a stream, aggregate by country and medal type, then serve cached rankings ordered by gold, silver, bronze, with fast recomputation from the event log.
Ans. I use inheritance in Java by creating a subclass with extends when it is a true specialised form of a superclass, and by implementing interfaces for shared behaviour contracts. The key detail is substitutability: any subclass should work wherever the parent type is expected. Otherwise, composition is usually safer and clearer.
Ans. Synchronization in operating systems is the coordination of processes or threads so they access shared resources safely and in the correct order. Its main purpose is to prevent race conditions and inconsistent data. Common mechanisms include mutexes, semaphores, locks, monitors, and condition variables, which enforce mutual exclusion or controlled waiting.
Ans. SQL is a language for storing, finding, and changing structured data, like a library catalogue. A table is a shelf list, rows are books, and columns are details such as title or author. SELECT finds books, WHERE filters them, JOIN connects related lists, and indexes work like a book index to speed searches.
Ans. Process scheduling is the operating system’s method for deciding which ready process gets the CPU next. The scheduler aims to share CPU time efficiently, improve responsiveness, and maximise throughput. Common policies include first come first served, shortest job first, priority scheduling, and round robin, with context switching used to move between processes.
Ans. String manipulation changes or analyses character sequences, while pointers store memory addresses used to access or modify data indirectly. The key detail is memory safety: in languages like C, strings need a null terminator and valid allocated space, and pointer arithmetic must stay within the same object or array.
Ans. An abstract class in Java is declared with abstract and is implemented by a subclass using extends, which must provide bodies for its abstract methods. It is used when related classes share common state or behaviour but some operations must be defined specifically by each subclass. Abstract classes cannot be instantiated directly.
Ans. A deadlock is a state where two or more processes are permanently blocked because each is waiting for a resource held by another. The necessary conditions are mutual exclusion, hold and wait, no preemption, and circular wait. Deadlock can occur only when all four conditions hold at the same time.
Ans. Count the total days between the birth date and today, then divide by 7 to get complete weeks. Each complete week contains one Tuesday. For the remaining days, check whether a Tuesday falls in that leftover range. Add 1 if it does. Clarify whether the start and end dates are included.
Ans. The Singleton pattern ensures a class has exactly one instance and provides a global access point to it. It is usually implemented by making the constructor private, storing a static instance inside the class, and exposing a static method or property to return it. In multithreaded code, creation must be thread safe.
Ans. Use arrays for fast index access, linked lists for frequent insertions and deletions, stacks for last-in-first-out tasks, queues for first-in-first-out tasks, hash tables for fast lookup, trees for sorted hierarchical data, heaps for priority access, and graphs for relationships. The key factor is the operation you need most often and its time complexity.
Ans. Use a sliding window of size k and count windows whose frequency map has exactly k-1 keys. Add the next character, remove the character leaving the window, and update the distinct count when frequencies become zero or one. This gives O(n) time and O(k) space.
Ans. Update the given node’s previous node to point to its next node, and its next node to point back to its previous node. Then free or discard the node. The key detail is handling ends: if there is no previous node, the caller must update the head pointer. This is O(1) time.
Ans. I would encrypt the file as a stream using an authenticated cipher such as AES-GCM, generating a fresh nonce and storing it with the ciphertext and tag. I would design a FileEncryptor, KeyProvider, CipherConfig, and FileHeader/Metadata object. The key detail is never reusing a nonce with the same key.
Ans. Merge Sort splits the array, recursively sorts halves, then merges them using a temporary array; Quick Sort chooses a pivot, partitions in place, then recursively sorts partitions. Merge Sort is always O(n log n) time and O(n) space. Quick Sort averages O(n log n), uses O(log n) stack space, but can degrade to O(n²).
Ans. Use abstract classes for shared state and behaviour, and interfaces for capabilities that different classes can implement. For example, an abstract Train could hold train number, route and coaches, while ExpressTrain and LocalTrain specialise it. Interfaces like Bookable, Cancellable and Refundable define contracts for tickets, reservations or payment services.
Ans. Copy the data from the next node into the given node, then change the given node’s next pointer to skip that next node. This deletes the logical node in O(1) time and O(1) space. The key limitation is that this only works if the given node is not the tail.
Ans. I would design a stable electric tricycle or tandem, not a standard solo bike. First I would define the use case, usually supervised riding on parks or cycle paths. Key features would be three wheels, low speed limit, audible navigation, obstacle sensors with haptic handlebar feedback, automatic braking, GPS tracking, bright visibility, and an emergency stop.
Ans. A blind-accessible cellular phone should be voice-first, tactile, and fail-safe. Architecture includes a standard cellular modem, low-power processor, screen reader, speech recognition, text-to-speech engine, haptic controller, physical keypad, emergency module, GPS, Bluetooth, and cloud sync. Specifications should prioritise long battery life, loud speaker, tactile buttons, offline voice commands, audio feedback, fall detection, and SOS calling.
Ans. Update the node’s previous neighbour to point to its next neighbour, and its next neighbour to point back to its previous neighbour. Then clear the deleted node’s prev and next references. This is O(1) time and O(1) space, but deleting the head requires access to, or returning, the updated head reference.
Ans. A Java program uses JDBC to connect to a database, send SQL statements, receive results, and turn them into application output. The usual flow is load the driver, open a connection, create a statement or prepared statement, execute the SQL, read the ResultSet row by row, then close resources. PreparedStatement is preferred for safety.
Ans. Build a prefix minimum array from the left and a suffix maximum array from the right, then scan both with two pointers to maximise j minus i where rightMax[j] is at least leftMin[i]. If the condition holds, move j forward; otherwise move i forward. This takes O(n) time and O(n) space.
Ans. Use the formula: for an m by n grid, the main diagonal crosses m + n − gcd(m, n) cells. Count rows and columns entered, then subtract the times the diagonal passes exactly through a grid intersection, because those would otherwise be counted twice. The gcd gives the number of equal segments.
Ans. I would design it as an order and inventory system with a menu, queue of customer orders, stock tracking, billing, and daily sales reports. Use a queue for pending orders, hash maps for item prices and ingredient stock, and a list for completed orders. The key detail is updating inventory atomically after each sale.
Ans. Semaphores are counters used to control access to shared resources, while mutual exclusion ensures only one thread or process enters a critical section at a time. A wait operation decrements the semaphore and may block; a signal operation increments it and may wake another process. Mutexes are binary semaphores commonly used to prevent race conditions.
Ans. Use a set to keep each character once, then sort the unique characters; for letters in “NIT KKR”, ignoring the space, the result is “IKNRT”. The key detail is to avoid repeated scanning: collect characters in a hash set or boolean array, then sort them, giving linear collection plus sorting time.
Ans. Copy the value from the next node into the given node, then change the given node’s next pointer to skip that next node. This effectively deletes the next node while making the given node look deleted. It works in O(1) time and O(1) space, but it cannot delete the tail node.
Ans. A strong answer should challenge the statistic politely, then discuss likely causes: burnout, weak mentoring, poor career paths, outdated skills, bad management, and lack of purpose. Use one real example from your experience or observation. Emphasise ownership, continuous learning, healthier delivery practices, coaching, and role mobility. Interviewers listen for maturity, balance, and practical solutions.
Ans. Traversal is O(n) for singly, doubly, and circular linked lists. Insertion and deletion are O(1) when the exact node or end pointer needed is already available, such as at the head. The important detail is that finding an arbitrary position first costs O(n), so overall insertion or deletion there is O(n).
Ans. Use an UPDATE statement naming the table, the columns to change, their new values, and a WHERE condition selecting the rows. The key detail is the WHERE clause: without it, the database updates every row in the table. For example, you would update a user’s email by filtering on that user’s id.
Ans. A JAR file is a Java Archive file that packages Java class files, resources, and metadata into a single compressed file. It is commonly used to distribute libraries or applications. A JAR can also include a manifest file, which may specify the main class to run an executable Java application.
Ans. OOPS in Java means organising code around objects that combine data and behaviour. The main concepts are encapsulation, inheritance, polymorphism, and abstraction. Encapsulation hides state using classes and access modifiers. Inheritance reuses behaviour. Polymorphism allows one interface to have many implementations. Abstraction exposes essential behaviour while hiding implementation details.
Ans. Reverse it by traversing the list once and swapping each node’s next and previous pointers. Keep moving using the pointer that was originally next, which becomes previous after the swap. At the end, update the head to the last processed node. This uses the existing nodes, runs in O(n) time, and uses O(1) extra space.
Ans. Choose a real example where you protected customer, employee, or company information on a social platform. Emphasise privacy settings, access control, approval processes, phishing awareness, and quick escalation of risks. Interviewers listen for judgement, respect for confidentiality, understanding of reputational impact, and evidence that you balance communication goals with data protection.
Ans. Common tree types include binary trees, binary search trees, balanced trees, heaps, tries, B-trees and expression trees. A binary tree has at most two children per node, while a BST orders values for efficient search. Balanced trees keep height small, heaps support priority access, tries store prefixes and B-trees optimise disk access.
Ans. JDBC connectivity in Java is the process of using the Java Database Connectivity API to connect a Java application to a database, send SQL queries, and read results. The main steps are loading the driver, creating a connection, preparing a statement, executing it, processing the result set, and closing resources.
Ans. HashMap stores key value pairs, while HashSet stores unique values only. Both use hashing, so lookup, insert and delete are average constant time. The key detail is that correctness depends on consistent hashCode and equals implementations. HashSet is internally backed by a HashMap, with each set element used as a key.
Ans. Runtime polymorphism in Java means the method that runs is chosen at runtime based on the actual object type, not the reference type. It is mainly achieved through method overriding, where a subclass provides its own implementation of a superclass or interface method. This enables flexible, extensible code.
Ans. A database is an organised collection of data, usually managed by a database management system. The key fundamentals are tables, rows, columns, keys, relationships, queries, indexes and transactions. Primary keys identify records, foreign keys link tables, SQL retrieves and changes data, and ACID transactions help keep data correct and reliable.
Ans. DBMS keys are attributes used to identify rows and define relationships between tables. A super key uniquely identifies a row, while a candidate key is a minimal super key. One candidate key becomes the primary key. An alternate key is an unused candidate key. A foreign key references another table, and a composite key uses multiple attributes.
Ans. A DBMS is software used to define, create, store, retrieve, update and manage data in a database. It acts as an interface between users or applications and the stored data, handling tasks such as queries, access control, data integrity, concurrency, backup and recovery. Examples include MySQL, PostgreSQL and Oracle.
Ans. Use Floyd’s cycle detection algorithm with two pointers, slow and fast. Move slow by one node and fast by two nodes each step. If they ever meet, the linked list has a cycle. If fast reaches null, there is no cycle. This takes O(n) time and O(1) extra space.
Ans. Swap the left and right child of every node in the binary tree. Do this with a depth first traversal: at each node, swap its children, then recurse on the left and right subtrees. The tree itself is modified in place. Time complexity is O(n), and recursion uses O(h) stack space.
Ans. Common types of computer networks are PAN, LAN, WLAN, CAN, MAN, WAN, SAN and VPN. The main difference is their scope: a PAN covers personal devices, a LAN covers a local area, a MAN covers a city, and a WAN connects large regions or countries, such as the internet.
Ans. Inheritance reuses and extends behaviour from a parent class, while abstraction hides implementation details and exposes only what users need. In Java, inheritance is mainly done with extends, and abstraction is done with abstract classes or interfaces. The key difference is that inheritance models “is a”, while abstraction defines “what it can do”.
Ans. Polymorphism is the ability for different object types to be treated through the same interface while providing their own behaviour. Abstraction is hiding implementation details and exposing only the essential operations. The key difference is that abstraction simplifies what a user sees, while polymorphism lets the same call behave differently depending on the object.
Ans. Merge Sort is a divide and conquer sorting algorithm that recursively splits an array into two halves, sorts each half, then merges the sorted halves into one sorted array. The key step is merging by comparing the smallest remaining elements from both halves. It runs in O(n log n) time and uses O(n) extra space.
Ans. Unix is preferred when reliability, automation, multiuser support and strong networking are important, especially on servers and developer systems. Its simple process model, powerful shell tools and file-based design make it easy to combine small programs, script repeated tasks and manage systems remotely with predictable behaviour.
Ans. A strong answer should focus on practical, system-level improvements: faster response times, centralised emergency numbers, GPS tracking, trained paramedics, better rural coverage, and hospital coordination. Pick an example from public health, logistics, or community service. Emphasise affordability, accountability, and technology. Interviewers listen for realism, empathy, and understanding of India’s scale.
Ans. Use cyclicity of last digits. Keep only the units digit of the base, then find its repeating pattern under powers. For example, 7 has cycle 7, 9, 3, 1. Divide the exponent by the cycle length and use the remainder to pick the digit. For sums or products, reduce each part modulo 10.
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Showing 60 of 101 questions. Ranked by how often the same question came back across interviews.
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Candidate interviews most often cover CS fundamentals (58%) and DSA (27%).
Candidate interviews show an average of 3.5 rounds per experience, with a typical sequence of Online test → Technical → HR. Individual interview paths can vary.
Among questions with a recorded difficulty, the mix is easy 57%, medium 41%, hard 2%.
