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Senior / Tech Lead Python Engineer

Exciting Opportunities for Tech Talent – Find Your Perfect Role!

Referral bonus: $800

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Lyubov Sokol

Recruiter at Ralabs

[email protected]

We are seeking a talented Tech Lead to join our dynamic team.

What is this project about?

An AI-powered analytics platform built for the defense domain. It ingests and analyzes data from multiple sources, automatically surfacing key findings and generating actionable insights and recommendations. By automating heavy manual analysis, the platform helps organizations make faster, better-informed decisions, reduce manual effort, and improve overall operational performance.

What is the team size and structure?

Project Manager, Business Analyst, Backend and ML Engineers, UI/UX Designer, DevOps, QA.

How many stages of the interview are there?

Recruiter interview – up to 30 minutes;
Technical interview – up to 1 hour;
Project fit interview – up to 45 minutes;
Polygraph screening.

Requirements and responsibilities

Hard skills

7+ years of professional Software Engineering experience, including experience leading technical delivery of complex backend systems;
Strong Python experience, including production development with FastAPI or similar asynchronous API frameworks;
Strong understanding of distributed systems, service-oriented architectures, service boundaries, data ownership, and independently deployable components;
Practical experience designing and implementing event-driven systems, including idempotency, retries, outbox patterns, durable state, asynchronous processing, and failure recovery;
Experience building long-running workflows with pause, resume, cancel, retry, timeout, and human-in-the-loop states;
Hands-on experience with PostgreSQL, Redis, OpenSearch/Elasticsearch, and S3-compatible object storage;
Experience building ingestion and data-processing pipelines for documents, structured data, images, video, audio, and geospatial materials;
Strong API design skills, including versioned contracts, OpenAPI, backward compatibility, typed request/response models, and service-to-service integrations;
Experience with authentication and authorization concepts such as OAuth2/OIDC, JWT, service identities, delegated authorization, RBAC, and ABAC;
Good understanding of Docker, Kubernetes, Helm, CI/CD, GitOps, secrets management, observability, and production diagnostics;
Ability to design for explicit latency, throughput, availability, recovery, scalability, and index-freshness targets;
Strong automated-testing practices covering unit, integration, security, and end-to-end testing;
Strong code-review skills and the ability to establish practical engineering standards without blocking delivery;
Ability to work with incomplete requirements, validate assumptions through focused PoCs, and convert architectural decisions into an executable delivery plan;
Strong documentation skills, including architecture diagrams, ADRs, sequence flows, API contracts, operational runbooks, and technical specifications;
High level of ownership, proactive decision-making, and ability to communicate technical trade-offs to engineering, product, ML, DevOps, security, and business stakeholders;
English – Upper-Intermediate.

Nice to have

Experience in the Defense/MilTech and AI domains;
Experience with on-premise/hybrid infrastructure;
Hands-on experience with LLM-based applications, RAG, tool calling, agent orchestration, structured outputs, context management, and grounded generation;
Understanding of AI security risks, including prompt injection, unsafe tool execution, untrusted content, sensitive-data leakage, and authorization bypass through retrieval or generated output;
Experience developing systems for air-gapped, disconnected, zero-egress, or highly restricted environments;
Experience with vector databases such as Qdrant or Milvus and hybrid dense/sparse retrieval;
Experience with Kafka or Redpanda, transactional outbox patterns, DLQs, and event-driven data processing;
Experience with Apache Iceberg, Trino, DuckDB, or similar analytical/lakehouse technologies;
Experience with SeaweedFS, MinIO, Ceph, or other S3-compatible object-storage systems.

Responsibilities

Drive the implementation process of the end-to-end architecture and hands-on implementation of critical platform components across system elements;
Implement production backend and platform functionality in Python, including critical services;
Take part in decomposition of the platform into clear service boundaries, data ownership areas, APIs, event flows, and integration contracts, ensuring that services access each other’s data only through authorized interfaces;
Define clear boundaries between backend application logic, data pipelines, ML processing, LLM reasoning, deterministic rules, security controls, and human validation;
Build retrieval integrations;
Integrate authentication, service identity, delegated tokens, RBAC/ABAC checks, compartments, classification controls, and audit events into backend services;
Write and maintain unit, integration, security, and end-to-end tests for inter-service workflows, authorization, persistence, retries, and failure scenarios;
Optimize critical paths for latency, throughput, concurrency, indexing freshness, reliability, and operational readiness;
Create focused PoCs to validate uncertain technical decisions and evolve successful PoCs into maintainable, observable, production-grade services without breaking end-to-end flows;
Translate product requirements and SRS modules into dependency-ordered engineering epics, milestones, estimates, technical acceptance criteria;
Identify architectural risks, bottlenecks, security gaps, technical debt, constraints, and external dependencies, and define practical mitigation options;
Establish engineering standards for code structure, testing, API versioning, logging, telemetry, deployment, backward compatibility, and release quality.

We offer

Work vibe

Flexible full-time/part-time hours
No micromanagement—time logging is for accounting only
High-quality equipment (MacBook or your own device)
Dynamic, low-bureaucracy environment
Team events, swag, and a great crew to hang with

Holidays and leaves

20 days of paid annual vacation;
15 days of paid sick leaves;
Possibility to use vacation during probation;
Maternity and paternity leave;
Days off on all government holidays.

Education

$100 annual education allowance
Mentorship program—learn or lead
English lessons with biannual reviews
Certification cost reimbursement
Free access to Udemy courses on request

Perks

Social package: medical insurance, sports compensation, or psychological training
IT Club Loyalty card (Lviv IT Cluster)
No overtime—work-life balance matters
Transparent payments in EUR/USD, on time every month
Assistance with military reservation procedure