New opportunity

Principal Software Engineer, AI Engineering

Context Labs · Cambridge, United States

About this role

Context Labs seeks a Principal Software Engineer to lead AI engineering for its Immutably™ Platform and analytics products in Cambridge, Massachusetts. Reporting to the VP, Engineering, the engineer will provide technical leadership on AI and large language models while developing systems that support the company’s data and climate-information products.

Responsibilities

  • Develop and maintain AI integrations, systems and services; turn business requirements into software tasks and model execution in collaboration with development teams and the product owner.
  • Fine-tune models for business use cases and build retrieval-augmented generation (RAG) systems. Provide exemplary designs, architecture and code; conduct code reviews; and oversee maintenance of AI systems.
  • Lead technical discussions on building, scaling and improving AI-system performance. Mentor engineers, work within an agile team and coordinate across a distributed team spanning multiple time zones.

Required experience and skills:

  • 10+ years of professional software systems development experience, with strong communication, attention to detail and comfort with abstract concepts and complex architectures.
  • Experience using LLM APIs for conversational AI and machine-driven insights; fine-tuning pretrained language models; designing and optimizing prompts; integrating API services; and building and deploying chatbots or virtual assistants.
  • Strong Java or other JVM-language coding skills, such as Scala; experience with Java frameworks such as Spring, Quarkus or Helidon; Docker-based microservices and Kubernetes; MySQL, PostgreSQL or equivalent relational databases; and NoSQL or NewSQL databases. Proficiency in unit and functional testing and source code management is also required.

Preferred

Functional programming experience, OpenAI API experience and a bachelor’s degree in computer science or a related field. This is a full-time position with an annual base compensation range of $170,000–$235,000.

For full details about this role, click “Apply on company site” to view the employer’s original posting.

Skills for this role

AI engineeringLarge language modelsLLM APIsModel fine-tuningRetrieval-augmented generationPrompt engineeringConversational AIChatbotsVirtual assistantsAPI integrationJavaScalaSpringQuarkusHelidonDockerMicroservicesKubernetesMySQLPostgreSQLRelational databasesNoSQLNewSQLUnit testingFunctional testingSource code managementSoftware architectureCode reviewAgile developmentTechnical leadership

Your skill match

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Get interview-ready for this role

A focused preparation guide, built around this job’s responsibilities and requirements.

✦ AI-generated guide
Preparation suggestions, not the employer’s actual interview questions. Always check the original posting for current requirements.
01

Understand the role

What matters most

  • Lead AI architecture and technical standards

    The role is the AI engineering team’s technical authority and calls for exemplary designs, architecture and code, plus code reviews. Prepare to explain architectural decisions you have led and how you made them usable by other engineers.

  • Turn product needs into model execution

    The engineer works with development teams and the product owner to define and estimate requirements, break them into software tasks, and implement model execution. Prepare a concise example of translating an ambiguous business need into a deliverable design.

  • Build business-specific LLM capabilities

    The posting calls for fine-tuning models, developing RAG systems, and using LLM APIs and prompts for conversational AI and machine-driven insights. Prepare to explain when you would choose each approach and how you would assess whether it serves the use case.

  • Deliver maintainable platform services

    The role develops and maintains AI integrations and services for the Immutably™ Platform and leads discussions on scaling and performance. The requirements emphasize JVM development, containerized microservices, Kubernetes, databases, and testing. Prepare to connect implementation choices to operability and maintenance.

  • Raise the team’s technical capacity

    The engineer will mentor less senior colleagues, lead technical talks, work in an agile team, and coordinate across time zones. Prepare examples of improving engineering decisions through reviews, coaching, and clear asynchronous communication.

Likely challenges to think through

  • Choosing the right LLM approach

    A likely design challenge is deciding whether prompt optimization, RAG, or fine-tuning best addresses a business case without adding unnecessary complexity. Prepare a decision framework covering evidence of quality, data needs, iteration effort, and maintenance; the posting does not specify a preferred approach.

  • Balancing AI performance with service maintainability

    Because the role spans model execution, scalable platform services, and ongoing maintenance, improving AI behavior may compete with latency and operational simplicity. Prepare to discuss how you would measure those trade-offs and isolate model-dependent components; no specific performance problem is stated.

  • Aligning decisions across teams and time zones

    Collaboration with a product owner, other development teams, and a distributed team could make requirements and architectural decisions harder to keep consistent. Prepare an example of documenting decisions, resolving disagreements, and maintaining momentum asynchronously; this is a coordination hypothesis, not a reported company issue.

03

Practice your answers

Technical practice

How would you turn a product requirement into a reliable AI-enabled service?

What to coverThe role involves working with development teams and a product owner to define, estimate and translate requirements into software tasks and model execution. Suggested preparation: explain how you would clarify expected behavior, divide the work, define interfaces and agree on acceptance tests.

How would you integrate an LLM API into a conversational application?

What to coverThe posting calls for LLM API integration and experience building and deploying chatbots or virtual assistants. Suggested preparation: cover conversation state, API failure handling, response quality and the trade-offs between latency, cost and functionality.

When would you fine-tune a pretrained language model rather than improve prompts or retrieval?

What to coverFine-tuning for business cases, prompt optimization and RAG development are all stated parts of the role. Suggested preparation: compare what each approach can change, the data and maintenance each needs, and how you would test whether it improves a specific task.

How would you design and evaluate a RAG system for a business requirement?

What to coverThe role explicitly includes developing RAG systems for business requirements. Suggested preparation: describe document preparation, retrieval, use of retrieved context and evaluation of both retrieval relevance and answer quality; treat the particular data and metrics as design choices, not known company practices.

How would you diagnose and improve an underperforming prompt?

What to coverThe posting requests proficiency in designing and optimizing prompts to elicit desired responses. Suggested preparation: explain how you would identify failure patterns, revise instructions or context, and compare results on representative cases without assuming one prompt will work universally.

How would you structure a JVM-based AI integration service?

What to coverThe role calls for Java or another JVM language, experience with Java frameworks and exemplary architecture and code. Suggested preparation: discuss separation of API, business logic and model-integration concerns, and justify framework choices through maintainability and service requirements.

How would you deploy and scale an AI microservice using Docker and Kubernetes?

What to coverDocker-based microservices, Kubernetes and technical leadership on AI-system scaling and performance are stated in the posting. Suggested preparation: address resource needs, rollout and recovery, and how you would distinguish service bottlenecks from model or external-API latency.

How would you choose between a relational database and a NoSQL or NewSQL database for an AI service?

What to coverThe posting names relational databases and NoSQL or NewSQL experience, but does not specify a schema or workload. Suggested preparation: compare consistency, query patterns, data shape and operational complexity against a clearly stated hypothetical use case.

What testing and review strategy would you use for changes to an AI integration?

What to coverThe role includes unit and functional testing, source code management and code reviews. Suggested preparation: distinguish deterministic service tests from checks of model-dependent behavior, and explain how review and versioned changes help prevent regressions.

How would you investigate a production AI service whose quality or performance has deteriorated?

What to coverThe posting includes ongoing maintenance and leading discussions about AI-system performance. Suggested preparation: describe how you would isolate integration, retrieval and model-behavior issues, then weigh a safe short-term mitigation against a measured long-term fix.

Behavioural practice

Tell me about a time you aligned teams on an ambiguous technical requirement.

What to coverThe role involves collaborating with development teams and a product owner to define and estimate requirements. Suggested preparation: use a real situation, explain how you resolved ambiguity and translated the decision into work, and state the result.

Tell me about a time you set an architectural direction without owning every implementation detail.

What to coverThe posting expects a principal engineer to provide exemplary designs and technical leadership. Suggested preparation: give a real situation, the trade-offs you explained and actions you took to gain alignment, followed by the outcome.

Tell me about a time you helped another engineer through a difficult technical problem.

What to coverCoaching and upskilling less senior engineers are explicit duties. Suggested preparation: describe the situation, how you supported independent problem-solving rather than simply taking over, and the result.

Tell me about a time you coordinated delivery across time zones.

What to coverThe role coordinates a distributed team spanning multiple time zones and works within an agile team. Suggested preparation: recount a real coordination challenge, your communication and handoff actions, and their effect on delivery.

Tell me about a time you used a code review or technical discussion to improve a system.

What to coverConducting code reviews and leading technical talks on building, scaling and performance are stated responsibilities. Suggested preparation: choose one real example, explain how you handled differing views and what changed as a result.

02

Sharpen your knowledge

Topics to prepare

  • LLM API and prompt design

    The posting requires LLM API integration for conversational AI and machine-driven insights, plus prompt optimization. For revision, diagram a request flow and compare two prompts against the same example inputs, explaining how you would judge response quality.

  • Fine-tuning and RAG trade-offs

    The role explicitly includes fine-tuning models and developing retrieval-augmented generation (RAG) systems for business cases. For revision, take one hypothetical business requirement and explain when you would use fine-tuning, RAG, or both, including how you would evaluate the result.

  • Scalable AI-service architecture

    The engineer is expected to provide architectural guidance and lead discussions on building, scaling, performance, and maintenance. For revision, sketch an AI service within the Immutably™ Platform and identify likely performance bottlenecks and maintenance boundaries; the sketch is a preparation exercise, not a stated platform design.

  • Data-store choices

    The posting calls for proficiency with relational databases such as MySQL or PostgreSQL and experience with NoSQL or NewSQL databases. For revision, compare where each type might fit in a hypothetical AI integration and explain the consistency and query needs behind your choices.

  • Principal-level technical leadership

    The role includes translating requirements with a product owner, reviewing code, mentoring engineers, and coordinating across time zones. For revision, rehearse how you would break an ambiguous AI requirement into estimated tasks and communicate an architectural decision for asynchronous review.

Skills to revise

  • Implement a JVM-based LLM integration

    The posting requires strong Java or other JVM-language coding, Java-framework experience, API integration, and conversational AI delivery. As practice, implement a small Java or Scala service endpoint that invokes a mock LLM API, handles failures, and returns a conversational response; use a listed framework if useful.

  • Build and check a RAG flow

    Developing RAG systems is an explicit responsibility. As practice, assemble a small set of sample documents, retrieve relevant passages for test questions, generate grounded answers, and inspect cases where retrieval or answers fail. This is a suggested exercise, not a specified company workflow.

  • Run a focused fine-tuning exercise

    The posting requires fine-tuning pretrained language models for specific tasks. As practice, define a small task-specific example set, compare model behavior before and after fine-tuning, and explain limitations in the comparison; no particular model or training tool is specified.

  • Package and deploy a microservice

    Docker-based microservices and Kubernetes are stated requirements. As practice, package the JVM service in Docker, draft its Kubernetes deployment configuration, and walk through how you would diagnose a failed rollout.

  • Test and review AI-service code

    Unit and functional testing, source code management, and code reviews are explicitly named. As practice, add tests for prompt construction, API failures, and an end-to-end service request; then review a change set for correctness and maintainability, explaining your feedback.

04

Your preparation checklist

  • Draft a requirements-to-execution example

    Prepare a one-page example of turning a business request into estimated software tasks and model execution. The role calls for this work with development teams and a product owner; use a hypothetical request rather than assuming a specific Immutably™ use case.

  • Prepare an AI project walkthrough

    Choose a relevant project, if available, and outline your decisions on LLM API integration, prompts, fine-tuning or RAG, testing, deployment and results. Distinguish what you built from what the wider team delivered.

  • Practice an AI-system design exercise

    Sketch a hypothetical service for conversational AI or machine-driven insights. Be ready to explain a Java or JVM implementation, API boundaries, database choices, Docker and Kubernetes deployment, and trade-offs in scaling, performance and maintenance.

  • Assemble engineering-quality evidence

    Select examples you can discuss of unit and functional tests, source-code practices and code reviews. Prepare to explain a design or code change you recommended and how you evaluated it.

  • Rehearse a principal-level leadership example

    Outline one example of leading a technical discussion or mentoring engineers, including how you handled architectural disagreement and coordinated work across teams or time zones.

  • Write questions for the employer

    Ask how AI work connects to the Immutably™ Platform and analytics products, which business cases currently drive fine-tuning or RAG, and how the team evaluates and maintains deployed AI systems.

AI-generated from the job information · Prepared Sep 30, 2026 (UTC)Useful preparation, not a guarantee of eligibility or an offer.

Availability last checked: Nov 4, 2026. Status can change after a check; confirm on the employer’s website. Report an issue · Our checking policy

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