Senior Backend Engineer

Description

Company Overview: Lean Tech is a rapidly expanding organization situated in Medellín, Colombia. We pride ourselves on possessing one of the most influential networks within software development and IT services for the entertainment, financial, and logistics sectors. Our corporate projections present numerous opportunities for professionals to advance their careers and experience substantial growth. Joining our team means engaging with expansive engineering teams across Latin America and the United States, contributing to cutting-edge developments in multiple industries.
Position Title: Senior Backend Developer 
Location: Remote - Colombia
What you will be doing: We are seeking an experienced Senior Backend Developer to design and build scalable microservices using and TypeScript. You will be responsible for moving logic to the edge Serverless infrastructure on AWS. Your daily challenges will revolve around optimizing Lambda cold starts, designing single-table schemas in DynamoDB, and ensuring our API Gateway layer is secure and performant. You are a developer who loves the speed of Typescript but demands the rigor of static typing and the scalability of the cloud. Your responsibilities will include:

• Design, develop, deploy, and maintain scalable serverless applications using AWS Lambda, implementing event-driven architectures triggered by API Gateway, S3 events, and DynamoDB services while adhering to AWS best practices for security, availability, and cost efficiency.
• Build, maintain, and enhance robust RESTful APIs using and TypeScript, enforcing strict type safety, interface contracts, and request/response validation to ensure reliable and consistent integrations.
• Design, manage, and optimize high-performance NoSQL data models, applying DynamoDB Single Table Design principles to support scalable access patterns, efficient indexing, and predictable performance.
• Monitor, analyze, and optimize serverless workloads by tuning AWS Lambda memory allocation, execution parameters, and concurrency limits, as well as adjusting DynamoDB throughput (RCU/WCU) to balance performance, scalability, and cost.
• Enforce high engineering quality standards through consistent linting and static analysis with ESLint, standardized code formatting using Prettier, and comprehensive unit and integration testing with frameworks such as Jest or Mocha.

Requirements & Qualifications To excel in this role, you should possess:

• Minimum of 5 years of professional experience in backend software development.
• At least 5 years of production experience developing applications with
• Minimum of 3 years of hands-on experience designing, building, and maintaining serverless applications on AWS.
• Deep expertise in and TypeScript, including advanced use of generics, utility types, interfaces, and strong typing strategies to build robust, maintainable codebases.
• Strong understanding of internals, including the event loop, non-blocking I/O, streams, and buffer management for high-performance backend systems.
• Advanced knowledge of asynchronous programming patterns, including async/await, Promises, and effective handling of concurrent executions (e.g., vs. Promise.allSettled).
• Extensive hands-on experience with the AWS serverless ecosystem, particularly AWS Lambda (lifecycle management, cold starts, layers), API Gateway (throttling, usage plans, authorizers, WebSocket APIs), and familiarity with AWS Step Functions for serverless orchestration.
• Solid expertise in NoSQL databases, with a strong understanding of DynamoDB concepts such as partition keys, sort keys, global secondary indexes (GSIs), and DynamoDB Streams; familiarity with MongoDB as an alternative NoSQL solution.
• Strong commitment to quality engineering practices, including test-driven development (TDD) and experience mocking external cloud services during automated testing.

Why you will love Lean Tech:

• Join a powerful tech workforce and help us change the world through technology
• Professional development opportunities with international customers
• Collaborative work environment
• Career path and mentorship programs that will lead to new levels. 

Join Lean Tech and contribute to shaping the data landscape within a dynamic and growing organization. Your skills will be honed, and your contributions will be vital to our continued success. Lean Tech is an equal-opportunity employer. We celebrate diversity and are committed to creating an inclusive environment for all employees.

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