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Interview preparation roadmap · Technology

Building products on large language models: retrieval, evaluation, ML basics and the back-end around them.

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  1. 01Interview foundations
  2. 02Coding
  3. 03ML foundations
  4. 04AI engineering
  5. 05Practice
  6. 06Company & final prep
CoreCommonly assessedGood to knowRole-dependentAdvancedFor deeper interviewsOptionalNot needed by everyoneCompletedYour progressYou are hereNext up
  1. 01Interview foundations

    What every interviewer sees first.

    1. 01.1Resume

      CoreBeginner3–5 h

      A one-page resume you can defend line by line.

      What this covers

      • One-page format — Reverse-chronological, clean fonts, no photos or tables that confuse parsers.
      • Project bullets — Action + what you built + a number (users, speed, accuracy).
      • Skills section — Only skills you can answer questions on for two minutes.
      • ATS readability — Export a text-based PDF and check it with a parser.
      • Working links — GitHub, LinkedIn and a live project link that open.
      • Tailoring — Reorder bullets to match the job description.

      What to practise

      • Run your PDF through a parser test
      • Rewrite each bullet as action + result
      • Remove any skill you can't explain for 2 minutes

      Common questions

      • Walk me through your resume.
      • Which project here are you most proud of, and why?
      • Why is this skill on your resume?

      Free resources

      • OpenResume — Free ATS-friendly resume builder and parser test (Free)
      • Jake's Resume (Overleaf) — The LaTeX resume template most SDE freshers use (Free)
      • Resume Worded — Resume and LinkedIn scoring (Free plan)
      • Jobscan — Match your resume against a job description (Free plan)

      Free courses

    2. 01.2Tell me about yourself

      CoreBeginner1–2 h

      A 60–90 second answer: present, past, why this role.

      What this covers

      • Present — Who you are now: degree, year, focus.
      • Past — One or two proof points: a project, internship or result.
      • Future — Why this role and this company next.
      • Length — 60–90 seconds; stop before you list everything.
      • Delivery — Calm pace and eye contact, not a memorised script.

      What to practise

      • Write it, then say it out loud 5 times
      • Record yourself and cut anything over 90 seconds

      Common questions

      • Tell me about yourself.
      • Why should we hire you?
      • Where do you see yourself in a few years?

      Free resources

      Free courses

    3. 01.3Behavioral & STAR

      CoreBeginner3–4 h

      Stories about teamwork, conflict and failure, told with STAR.

      What this covers

      • STAR structure — Situation, task, action, result. Spend most of the time on action.
      • Story bank — 6–8 real stories you can reuse across questions.
      • Teamwork & conflict — Disagreeing respectfully and what you changed.
      • Failure & weakness — A real one, what you learned, what you do now.
      • Ownership — Times you took initiative without being asked.
      • Common HR questions — Why us, why you, strengths, relocation.

      What to practise

      • Write 6 stories in STAR form
      • Map each story to 2–3 common questions
      • Practise one story with a friend

      Common questions

      • Tell me about a time you failed.
      • Describe a conflict in a team and what you did.
      • What is your biggest weakness?

      Free resources

      Free courses

  2. 02Coding

    Most loops include coding.

    1. 02.1Programming fundamentals

      CoreBeginner6–10 h

      One language you know well: syntax, memory, complexity.

      What this covers

      • One language deeply — C++, Java or Python: syntax, standard library, quirks.
      • Time & space complexity — Big-O of loops, recursion and common operations.
      • Recursion — Base cases, the call stack, when it overflows.
      • Memory basics — Stack vs heap, references vs values, garbage collection.
      • Strings & arrays — Immutability, copying and slicing costs in your language.
      • Debugging — Reading errors, dry runs, using a debugger.

      What to practise

      • Solve 10 easy problems without an IDE's help
      • Explain the complexity of each solution aloud

      Common questions

      • What is the time complexity of your solution?
      • What happens in memory when you call a function?
      • Difference between an array and a linked list?

      Free resources

      Free courses

    2. 02.2Core Python

      CoreIntermediate6–10 h

      Python language questions for Python roles.

      What this covers

      • Data types — Mutability, lists vs tuples, dicts and sets.
      • Functions — args, kwargs, closures, decorators.
      • Iterators & generators — yield and lazy evaluation.
      • OOP in Python — Classes, dunder methods, inheritance.
      • Error handling — Exceptions and context managers.
      • Performance — The GIL, list comprehensions, profiling.

      What to practise

      • Write a decorator that times a function
      • Solve 15 problems in idiomatic Python

      Common questions

      • What is a decorator?
      • Difference between a list and a tuple?
      • What is the GIL?

      Free resources

      • Harvard CS50x — The best first CS course there is (Free)
      • Exercism — Practice exercises with human mentoring (Free)
      • Kaggle Learn — Short practical courses: Python, Pandas, ML, SQL (Free)

      Free courses

    3. 02.3Data structures & algorithms

      Good to knowIntermediate40–80 h

      The core problem-solving topics commonly assessed in software interviews.

      What this covers

      • Arrays & hashing — Frequency maps, prefix sums, duplicates.
      • Two pointers & sliding window — Pairs, subarrays and substrings in O(n).
      • Stacks & queues — Brackets, monotonic stacks, BFS queues.
      • Linked lists — Reversal, cycle detection, merging.
      • Trees & BST — Traversals, height, LCA, validation.
      • Graphs — BFS, DFS, topological sort, shortest paths.
      • Binary search — On sorted arrays and on the answer.
      • Dynamic programming — 1D and 2D DP, from climbing stairs to knapsack.

      What to practise

      • Follow one list end to end, not five
      • Say the brute force first, then improve it
      • One timed problem a day

      Common questions

      • What is the difference between BFS and DFS?
      • How does a hash map handle collisions?
      • Find the first non-repeating character in a string.

      Free resources

      Free courses

  3. 03ML foundations

    What sits under LLM apps.

    1. 03.1Machine learning fundamentals

      CoreIntermediate15–25 h

      Core ML concepts asked in data scientist and ML interviews.

      What this covers

      • Supervised learning — Regression, classification, common algorithms.
      • Bias–variance — Underfitting, overfitting, regularisation.
      • Evaluation — Train/test splits, cross-validation, precision, recall, ROC.
      • Feature engineering — Encoding, scaling, leakage.
      • Trees & ensembles — Random forests and gradient boosting.
      • Unsupervised learning — Clustering and dimensionality reduction.

      What to practise

      • Train and evaluate a model on a public dataset
      • Explain precision vs recall with your own example

      Common questions

      • What is overfitting and how do you prevent it?
      • When would you use precision over recall?
      • How does a random forest work?

      Free resources

      Free courses

    2. 03.2Deep learning

      Good to knowAdvanced15–25 h

      Neural networks, training and modern architectures.

      What this covers

      • Neural network basics — Layers, activations, backpropagation.
      • Training — Loss functions, optimisers, learning rates.
      • Regularisation — Dropout, batch norm, data augmentation.
      • CNNs — Convolutions for images.
      • Transformers — Attention and why it works.
      • Frameworks — PyTorch or TensorFlow basics.

      What to practise

      • Train a small CNN and explain its errors
      • Implement a tiny neural net from scratch

      Common questions

      • What is backpropagation?
      • Why do we need activation functions?
      • What is attention?

      Free resources

      Free courses

    3. 03.3Natural language processing

      Good to knowAdvanced10–15 h

      Text representations, transformers and evaluating language models.

      What this covers

      • Text preprocessing — Tokenisation, subwords.
      • Embeddings — Word and sentence vectors.
      • Transformers — Encoders, decoders, attention.
      • Tasks — Classification, NER, summarisation, QA.
      • Evaluation — Accuracy, F1, BLEU/ROUGE and their limits.

      What to practise

      • Fine-tune a small text classifier
      • Compare two embedding models on a task

      Common questions

      • How does a transformer work?
      • What is tokenisation?

      Free resources

      Free courses

  4. 04AI engineering

    The main role-specific rounds.

    1. 04.1LLM applications

      CoreAdvanced8–12 h

      Building products on top of large language models and evaluating them.

      What this covers

      • Prompting — Instructions, examples, structured outputs.
      • Retrieval (RAG) — Chunking, embeddings, vector search.
      • Evaluation — Test sets, human review, failure analysis.
      • Fine-tuning basics — When it helps and when it does not.
      • Safety & cost — Hallucinations, privacy, latency, tokens.

      What to practise

      • Build a small RAG demo over your own notes
      • Write an evaluation set of 20 cases for it

      Common questions

      • How does retrieval-augmented generation work?
      • How do you evaluate an LLM feature?

      Free resources

      Free courses

    2. 04.2Back-end & API design

      CoreIntermediate8–12 h

      Designing, securing and scaling the APIs your projects expose.

      What this covers

      • REST design — Resources, verbs, status codes, versioning.
      • Authentication — Sessions, JWT, OAuth at a basic level.
      • Validation & errors — Consistent error shapes and input checks.
      • Pagination & filtering — Cursor vs offset pagination.
      • Rate limiting & idempotency — Protecting APIs and safe retries.
      • One framework deeply — Express, Spring Boot, Django or FastAPI.

      What to practise

      • Build a CRUD API with auth and tests
      • Write the API docs for one of your projects

      Common questions

      • How would you design a REST API for a library?
      • What is idempotency?
      • How does JWT authentication work?

      Free resources

      Free courses

    3. 04.3MLOps

      Good to knowAdvanced8–12 h

      Shipping and running ML models reliably.

      What this covers

      • Experiment tracking — Reproducible runs and versioned data.
      • Pipelines — Training and evaluation automation.
      • Model serving — APIs, batch jobs, scaling.
      • Monitoring — Data drift and model decay.
      • CI/CD for ML — Testing data and models.

      What to practise

      • Serve a model behind an API in a container
      • Add drift monitoring to a toy model

      Common questions

      • How do you know a model in production is degrading?
      • How would you version datasets?

      Free resources

      Free courses

    4. 04.4System design basics

      Good to knowAdvanced10–20 h

      More common for experienced roles; some fresher rounds touch it.

      What this covers

      • Client–server basics — Requests, APIs, stateless servers.
      • Load balancing — Spreading traffic across servers.
      • Caching — What to cache, where, and invalidation.
      • Databases at scale — SQL vs NoSQL, replication, sharding.
      • Queues — Async work and decoupling.
      • Classic problems — URL shortener, chat, news feed.

      What to practise

      • Design a URL shortener on paper
      • Explain trade-offs, not just boxes

      Common questions

      • Design a URL shortener.
      • How would you scale a read-heavy app?

      Free resources

      Free courses

    5. 04.5Projects & resume defense

      CoreIntermediate4–6 h

      Explaining what you built, why, and what you would change.

      What this covers

      • The problem — What it solves and for whom.
      • Your role — Exactly what you built yourself.
      • Architecture — A simple diagram: frontend, backend, database.
      • Hardest bug — What broke and how you found it.
      • Trade-offs — Why this stack; what you would change now.
      • Scale questions — What happens with 10x the users.

      What to practise

      • Prepare a 2-minute walkthrough per project
      • Be ready to draw its architecture

      Common questions

      • What was the hardest part of this project?
      • Why did you choose this tech stack?
      • How would it handle 10x more users?

      Free resources

      Free courses

  5. 05Practice

    Saying it out loud is a different skill.

    1. 05.1Technical mock interviews

      CoreIntermediate3–6 h

      At least two full coding mocks before the real one.

      What this covers

      • Thinking aloud — Narrate your approach before and while coding.
      • Clarifying questions — Confirm inputs, scale and edge cases first.
      • Handling hints — Take them gracefully and adapt.
      • "I don't know" — Say what you do know and how you would find out.
      • Review the recording — Fillers, pace, unclear explanations.

      What to practise

      • Do two peer mock interviews
      • Record one spoken mock and listen back

      Common questions

      • Walk me through your approach before you code.
      • How would you test this?

      Free resources

      Free courses

    2. 05.2Technical communication

      Good to knowBeginner2–3 h

      Explaining your thinking clearly in English.

      What this covers

      • Structure — Big picture first, then details.
      • Plain words — Explain without jargon.
      • Checking in — "Does that make sense so far?"
      • Written English — Clear emails and follow-ups.

      What to practise

      • Explain one project to a non-CS friend
      • Record a 2-minute explanation of your best project and listen back

      Common questions

      • Explain recursion to a 10-year-old.

      Free resources

      Free courses

  6. 06Company & final prep

    The last 48 hours.

    1. 06.1Company research

      CoreBeginner1–2 h

      The product, the role, the job description and recent news.

      What this covers

      • The business — What it sells and to whom.
      • The role — What the job description really asks for.
      • Recent news — Launches, results, announcements.
      • Interview format — The rounds, if the company shares them.
      • Your fit — Three reasons, matched to the job description.

      What to practise

      • Write 3 reasons you want this role
      • Match 3 JD lines to your experience

      Common questions

      • Why do you want to work here?
      • What do you know about our product?

      Free resources

    2. 06.2Questions to ask

      Good to knowBeginner30 min

      Two or three good questions for the end of the interview.

      What this covers

      • About the team — How work is planned and reviewed.
      • About growth — Mentoring, learning, the first 90 days.
      • About the product — What is hard right now.
      • What to avoid — Questions a quick search answers.

      What to practise

      • Write 5 questions, keep the best 3
      • Prepare one question about the team's own product

      Common questions

      • Do you have any questions for us?

      Free resources

    3. 06.3Final checklist

      CoreBeginner30 min

      Logistics, documents, setup and a calm night before.

      What this covers

      • Logistics — Time, timezone, link or address.
      • Documents — Resume copies, ID, certificates if asked.
      • Tech check — Camera, mic, internet, charger.
      • Night before — Sleep, light revision, no new topics.

      What to practise

      • Do a 5-minute tech check the day before
      • Lay out documents and clothes the night before

      Free resources

    4. 06.4Job & interview safety

      Good to knowBeginner15 min

      Spot fake offers, payment requests and fake interview links.

      What this covers

      • Payment requests — Real employers don't charge for jobs or training.
      • Email domains — Check it matches the company's own site.
      • OTPs & logins — Never share them with anyone.
      • Fake interview links — Care with unknown chat apps and downloads.
      • Reporting — The 1930 helpline and cybercrime.gov.in.

      What to practise

      • Check one recent offer against these rules
      • Confirm the opening is listed on the company's own careers page

      Free resources

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