Senior Backend Engineer
Posted 6 hours 59 minutes ago by Xcede
600,00 € Daily
Contract
Not Specified
Other
Barcelona, Spain
Job Description
There are two Back End roles here, both sitting within the same product-led SaaS environment, but with slightly different focus areas. Both are senior, hands-on positions in a brownfield setup, so the emphasis is on improving and extending existing systems rather than building from scratch.
Role 1 - core Back End/platform services
This role sits within the core Back End platform team. The work is centred around maintaining and evolving existing Go services that underpin the product.
What you'll be doing
Working on production Go services, improving performance, reliability and maintainability
Owning features end to end from product requirements through to implementation
Designing and evolving PostgreSQL schemas, writing efficient queries and handling migrations safely in a live environment
Contributing to a distributed, event-driven architecture using Kafka or similar
Deploying and running services via Docker and Kubernetes in AWS
Working with a fair degree of autonomy where product requirements are defined but technical approach is not always prescribed
What matters for this role
Strong experience in brownfield Go environments, not just greenfield builds
Deep understanding of PostgreSQL in production systems
Solid grasp of microservices and event-driven patterns
Ability to make pragmatic engineering decisions without heavy oversight
Comfortable using AI coding tools as part of your workflow, but able to validate and iterate on outputs properly
Nice to have here includes exposure to Temporal for workflows, Twilio integrations and additional Back End languages such as Node.js or TypeScript.
This is the more "traditional" Back End role, focused on platform stability, scalability and ongoing product evolution.
Role 2 - AI/agentic systems
This role is more focused on building out newer AI-driven capabilities within the platform. It still requires strong Go fundamentals, but the work is more exploratory and centred around agent-based systems.
What you'll be doing
Building and integrating agents, agentic tooling and MCP-style Servers into the existing platform
Prototyping and iterating quickly on AI-driven features, then hardening them for production use
Working from loosely defined problems, evaluating different approaches and selecting the most effective solution
Integrating with existing Back End services and data layers, including PostgreSQL
Using AI coding agents heavily to accelerate development and delivery
What matters for this role
Strong Go experience in real-world systems, again with a focus on existing services rather than greenfield only
Practical experience building or working with agents or agent-based tooling
Comfort operating in ambiguity, where problems are not fully defined upfront
Ability to move quickly from idea to working solution, then iterate
Sensible use of AI tooling - fast, but with proper validation and engineering judgement
Nice to have includes exposure to AgentCore, some Python or Node.js and any Front End exposure such as React.
Role 1 - core Back End/platform services
This role sits within the core Back End platform team. The work is centred around maintaining and evolving existing Go services that underpin the product.
What you'll be doing
Working on production Go services, improving performance, reliability and maintainability
Owning features end to end from product requirements through to implementation
Designing and evolving PostgreSQL schemas, writing efficient queries and handling migrations safely in a live environment
Contributing to a distributed, event-driven architecture using Kafka or similar
Deploying and running services via Docker and Kubernetes in AWS
Working with a fair degree of autonomy where product requirements are defined but technical approach is not always prescribed
What matters for this role
Strong experience in brownfield Go environments, not just greenfield builds
Deep understanding of PostgreSQL in production systems
Solid grasp of microservices and event-driven patterns
Ability to make pragmatic engineering decisions without heavy oversight
Comfortable using AI coding tools as part of your workflow, but able to validate and iterate on outputs properly
Nice to have here includes exposure to Temporal for workflows, Twilio integrations and additional Back End languages such as Node.js or TypeScript.
This is the more "traditional" Back End role, focused on platform stability, scalability and ongoing product evolution.
Role 2 - AI/agentic systems
This role is more focused on building out newer AI-driven capabilities within the platform. It still requires strong Go fundamentals, but the work is more exploratory and centred around agent-based systems.
What you'll be doing
Building and integrating agents, agentic tooling and MCP-style Servers into the existing platform
Prototyping and iterating quickly on AI-driven features, then hardening them for production use
Working from loosely defined problems, evaluating different approaches and selecting the most effective solution
Integrating with existing Back End services and data layers, including PostgreSQL
Using AI coding agents heavily to accelerate development and delivery
What matters for this role
Strong Go experience in real-world systems, again with a focus on existing services rather than greenfield only
Practical experience building or working with agents or agent-based tooling
Comfort operating in ambiguity, where problems are not fully defined upfront
Ability to move quickly from idea to working solution, then iterate
Sensible use of AI tooling - fast, but with proper validation and engineering judgement
Nice to have includes exposure to AgentCore, some Python or Node.js and any Front End exposure such as React.