Principal Engineer (backend)

Sage City; Bengaluru; Hybrid; INR 3,500,000 - 7,000,000; Full time

Job summary

Sage City in Bangalore, India is seeking a Principal Backend Engineer to lead the design and delivery of high‑quality SaaS services. The role requires 10+ years of backend experience, strong TypeScript/Node.js, and hands-on cloud, DB, and distributed systems expertise.

This is a hybrid position with three days in the office in Bangalore. You will mentor engineers, drive architectural decisions, and collaborate with cross‑functional teams to ensure robust, scalable products and software quality.

Qualifications

• 10+ years of backend engineering experience.
• Strong knowledge of scalable SaaS backends and cloud services.
• Production-grade Node.js with TypeScript in modern stacks.
• Proficient in REST API design, versioning, and OpenAPI specs.
• Experience with distributed systems, caching, and data stores.

Responsibilities

• Lead the design, development, and delivery of scalable SaaS backend services.
• Provide technical ownership, code reviews, and architectural guidance.
• Collaborate with product, security, and QA for reliable releases.
• Identify bottlenecks, security gaps, and debt; drive improvements.
• Advance tooling, CI/CD, and development processes across teams.

Skills

TypeScript

Node.js

REST API design

Fastify/Express/NestJS/Koa

OpenAPI/Swagger

JSON Schema/AJV

AWS SQS / Kafka / RabbitMQ

Redis

Docker

Kubernetes

OAuth2 / OIDC / JWT

OWASP Top 10

Multi-tenant isolation

Testing (Vitest/Jest)

CI/CD (GitHub Actions)

Git & PR workflows

Monorepo Nx

AI tooling integration

Tools

Fastify

Express

NestJS

Koa

AJV

OpenAPI

Knex

Redis

MySQL / PostgreSQL

Docker

Kubernetes

AWS services (S3, IAM, ECR)

ArgoCD

GitHub Actions

Job description

Job Description About the RoleAs a Principal Backend Engineer at Sage, you will provide technical leadership in designing, developing, and delivering a high-quality SaaS solution that exceeds customer and business partner expectations. We are looking for someone with 10+ years of professional experience in backend engineering, who can bring technical depth, architectural vision, and leadership maturity to the team. Proficiency in English, written and verbal, is required.We value humility and collaboration. We are looking for people who can work as part of a team, not in silos. We expect engineers to take ownership beyond just writing code, including tests, documentation, and long-term code quality.Location: Bangalore, India. This is a hybrid role, three days per week in the office.Required SkillsCore languages & runtime Strong TypeScript (strict mode) and Node.js (v24+) for production services. Solid computer-science fundamentals: data structures, algorithms, concurrency, async I/O.Backend frameworks & APIs REST API design with Fastify (or Express/NestJS/Koa with willingness to learn Fastify). JSON Schema contract design and validation (AJV or equivalent); OpenAPI/Swagger. Understanding of API versioning, idempotency, pagination, and error-handling patterns.Data & persistence Relational databases MySQL and/or PostgreSQL: schema design, indexing, query tuning. Comfort with JSON-document modeling in a relational store and query compilation to SQL. SQL query builders (Knex or similar); parameterized queries and SQL-injection prevention. Caching with Redis.Distributed systems & messaging Event-driven / message-queue systems (AWS SQS, or Kafka/RabbitMQ/SNS equivalents): producer/consumer patterns, dead-letter queues, retries/backoff, and idempotency. Designing for at-least-once delivery and eventual consistency.Cloud & platform AWS services (SQS, EFS, S3, IAM, ECR) in a production context. Containerization with Docker; familiarity with Kubernetes deployments.Security OAuth2 / OIDC / JWT validation (RS256, JWKS), token propagation, and multi-issuer auth. Secure coding against the OWASP Top 10; multi-tenant isolation and row-level security.Testing & quality Unit, integration, and contract testing (Vitest/Jest or equivalent); test-driven mindset. Linters/formatters (Biome, ESLint/Prettier) and CI discipline.Tooling & workflow Git and pull-request workflows; monorepo experience (Nx) a plus. CI/CD (GitHub Actions or similar).AI Tooling Productive use of AI-assisted developer tooling (e.g. GitHub Copilot, Claude Code, Cursor) to accelerate day-to-day backend development. Integrating LLM / generative-AI capabilities into backend services (e.g. OpenAI, Anthropic, AWS Bedrock) via SDKs, streaming responses, and prompt/response validation. Familiarity with retrieval-augmented generation (RAG): embeddings, vector stores/search, and context assembly pipelines.Nice to Have Experience with MongoDB-like query languages or building a query compiler/DSL. KEDA / autoscaling on queue depth; Istio service mesh; Argo Rollouts canary deploys. GitOps (ArgoCD) and schema-driven DB migrations (Atlas or Liquibase/Flyway). Observability stacks: New Relic APM, Sumo Logic, Prometheus, Pino logging. Experience with git-like versioning / CRDT / operational-transform data models. Domain knowledge in finance, ERP, FP&A, or accounting systems. Building data-migration / reconciliation frameworks at scale. Experience building AI/ML-powered backend features such as forecasting, anomaly detection, or natural-language querying over financial data.#LI-RTKey Responsibilities Responsibilities Lead the design, development, and implementation of scalable, high-performance SaaS software Take technical ownership of products, systems, or services, ensuring robust and maintainable solutions. Provide guidance and mentorship to software engineers, fostering technical growth within the team and contribute to code reviews, architectural discussions, and technical design sessions. Collaborate with cross-functional teams, including product management, architecture, and quality assurance, to ensure successful product delivery. Identify and address performance bottlenecks, security vulnerabilities, and technical debt and act as a technical expert in solving complex software challenges. Drive continuous improvement in software development processes, tools, and methodologies. Stay current with emerging technologies and industry trends, applying them to improve product efficiency and quality.#LI-RT