Senior Backend Engineer (Python)

Company: HealthifyMe

Experience: 4 - 6 years

About the Role:

We're looking for a backend engineer who genuinely enjoys understanding how systems work under the hood.

Someone who doesn't just know how to use a database, but understands how indexes work, why queries slow down, what happens during concurrent transactions, and how to safely migrate data while production systems are handling heavy traffic.

We value strong engineering fundamentals, technical depth, and sound design principles. We're looking for someone who can understand a problem end to end, question design decisions, evaluate tradeoffs, and build reliable, scalable systems from the ground up.

What We're Looking For:

- Strong Python backend experience: Hands-on production experience with Django, FastAPI, or Python-based microservices. You should be comfortable designing, building, debugging, and owning services independently.

- Deep database understanding: Strong knowledge of SQL, particularly MySQL, including indexing, query optimization, transactions, locking, concurrency, and database internals. Familiarity with Elasticsearch, time-series databases, and different data storage patterns is valuable.

- Production migrations at scale: Experience handling schema changes, data migrations, or infrastructure migrations on live systems under significant traffic. Understanding zero-downtime strategies, backward compatibility, and rollback planning matters.

- Payment systems: Experience designing or maintaining scalable payment services. You should understand idempotency, retries, reconciliation, failure handling, and the challenges of building reliable financial transaction flows.

- Third-party integrations: Experience integrating external services and APIs, handling rate limits, timeouts, retries, webhooks, and failure scenarios.

- System design and scalability: Strong understanding of caching, load balancers, CDNs, asynchronous processing, message queues, concurrency, and distributed systems fundamentals.

- Strong software design principles: Deep understanding of abstraction, modularity, separation of concerns, design patterns, and clean architecture. More importantly, knowing when and why to apply these principles in production, and when not to overengineer.

- End-to-end ownership: Ability to take a requirement, understand the underlying problem, evaluate alternatives, design a solution, implement it, and take responsibility for how it behaves in production.

Good to Have :

- Hands-on DevOps experience or strong understanding of infrastructure, AWS, containers, deployments, networking, and production debugging.

- Experience building AI-powered microservices, LLM integrations, agent workflows, or AI orchestration systems.

- Understanding of API communication patterns and protocols, including REST, GraphQL, gRPC, and their underlying tradeoffs.

- Experience investigating and solving performance bottlenecks across application, database, and infrastructure layers.