Senior Backend Engineer

Senior Backend Engineer

The Senior Backend Engineer plays a critical role in designing and scaling the core systems that power DOOR's platform. This position is responsible for building resilient, high-performance backend services that support real-time data, device communication, and intelligent automation across our ecosystem. This role helps drive the evolution of our architecture toward modern, cloud-native, and event-driven systems—ensuring our platform remains scalable, secure, and ready to support rapid growth and innovation, including AI-enabled capabilities.

This is a highly technical, hands-on engineering role focused on building and optimizing backend services within a JVM-first, cloud-native environment. You will design and develop microservices using Kotlin/Java and Spring Boot, create robust APIs (REST and gRPC), and build event-driven systems leveraging Kafka and AWS messaging services.

You'll own key architectural decisions across data storage, system performance, and security, working across technologies like PostgreSQL, MongoDB, Redis, and AWS infrastructure. This role also involves driving infrastructure-as-code practices, implementing observability and monitoring, and contributing to the modernization of legacy systems.

As a senior member of the team, you will operate with a high degree of autonomy, mentor other engineers, and partner closely with product, frontend, data, and platform teams to deliver scalable, reliable solutions. You will help shape engineering best practices while balancing speed, quality, and long-term maintainability.

DOOR (formerly Latch) is unlocking the next era of Building Intelligence. We combine premium hardware, intuitive software, and automated operations into one seamless platform—helping multifamily properties run more efficiently, grow revenue, and deliver smarter, more connected living experiences. From smart access and in-unit automation to building-wide controls, DOOR empowers owners, operators, and property teams to reduce overhead, protect asset value, and stand out in a competitive market.

We believe smarter buildings make life simpler. At DOOR, you'll help shape a future where buildings anticipate needs, operate effortlessly, and quietly improve life for everyone inside.

What will you do?

• Design and implement microservices using Kotlin/Java (JVM 21) with Spring Boot (MVC).
• Build and maintain APIs (REST + gRPC) with strong contract design (OpenAPI, Protobuf).
• Develop event-driven systems using SQS/SNS and/or Kafka.
• Own data layer design across PostgreSQL, MongoDB, and Redis (caching, locking).
• Lead architecture decisions for scalability, resilience, and security (OAuth2/JWT, IAM, KMS).
• Drive cloud-native infrastructure on AWS (Lambda, S3, RDS, CloudFront) with Terraform.
• Implement CI/CD, observability (OpenTelemetry, logging), and production monitoring.
• Contribute to system modernization and migration from legacy systems.
• Mentor engineers and participate in technical leadership and roadmap definition.
• Collaborate cross-functionally with product, data, frontend and platform teams.

What do you bring to DOOR?

• 5-10+ years of backend engineering experience.
• Strong English communication skills.
• Strong proficiency in JVM stack: Kotlin and/or Java.
• Deep experience with Spring Boot ecosystem (Data, Security, Web, Reactive).
• Experience designing distributed systems and microservices architectures.
• Hands-on with AWS cloud services and infrastructure-as-code (Terraform or similar).
• Strong database experience: PostgreSQL + NoSQL (MongoDB/Redis).
• Experience with messaging systems (SQS/SNS, Kafka).
• Solid understanding of system design, OOP, and design patterns.
• Experience with Docker and Kubernetes-based deployments.

Preferred Qualifications

• Experience with gRPC and Protobuf-based service design.
• Exposure to event-driven and reactive systems (Reactor, Coroutines).
• Background in high-scale, secure systems (IoT, payments, or similar).
• Experience with AI/LLM integrations, vector databases, or RAG systems.
• Familiarity with security, compliance, and data protection (PII/GDPR).

What is required?

• Location: Must be based in South America (preference for Argentina, Brazil, Colombia, Peru, Uruguay, or Chile)
• Must be able to work fully remote and align with U.S. time zones (Eastern/Central hours)
• Must be fluent in written and spoken English
• This role will be engaged as an independent contractor; candidates must be able to invoice for services and manage their own taxes locally.

DOOR understands that job requirements sometimes exclude people who identify with historically marginalized groups from applying to jobs for which they are qualified. Even if you don't meet 100% of the requirements listed, or if you achieved these requirements through unconventional channels, we encourage you to apply.

What does DOOR bring to the table?

• Flexible Time Off We offer a flexible time off policy to ensure employees have the opportunity to rest, recharge, and maintain well-being—so they can bring their best selves to work.

Joining us means:

• Having teammates all over the world in the US, Argentina, Spain and Romania.
• Collaborating in a fast-paced environment where you can apply what you have learned in new challenges, and, more importantly, grow your career.
• Being encouraged to invent and innovate within your role and working in a company where calculated risk-taking is highly encouraged and thinking outside the box is a must.

We embrace diversity and strive to create an inclusive environment for all.

Attention Job Seekers: Beware of job scams!

Job scams are on the rise, and you should take steps to protect yourself in your job search. Here are some guidelines to help you stay safe if you are applying for a job with Latch or DOOR:

• Communications from Latch or DOOR will always come from @latch.com or @door.com. Do not accept a job interview invitation with Latch or DOOR from anyone who does not contact you through an email that comes from @latch.com or @door.com.
• Latch never interviews candidates via Skype or in writing where you do not see the interviewer. All of our interviews happen either by video or in person.
• We will never offer you a job based on a single conversation with someone claiming to be from our People organization. In all of our job interviews, you will always speak, by video or in person, with the hiring manager for the position.
• Do not share your sensitive personal information with anyone who purports to offer you a job at Latch or DOOR unless you verified that the offer is from Latch or DOOR (check email senders addresses). We will never ask you for your bank account information or your mother's maiden name during the interview process.
• We will never ask you to purchase any equipment with a promise that we will reimburse you after you begin working for us.
• If you believe you were a victim of a job scam, you may report it to the FBI: