Freelance Backend Jobs

Build and maintain backend services for software products, with Java engineering as the main focus. You’ll contribute across the product lifecycle, from design and implementation…

Design and maintain the data architecture that connects organizational data assets, services, and flows. This contractor role provides architectural direction for new initiatives…

Build reliable payment capabilities for purchases that begin in an AI agent conversation. You’ll connect conversational checkout to payment providers and order services, ensuring…

Build the developer facing tools that let teams connect AI agents to websites and other products. The work spans APIs, client libraries, embedding options, and integration guidanc…

Secure customer-facing AI agents and the data and services they can access. You’ll assess how agents, integrations, and access controls could be abused, then implement protections…

Design and build protocol features for a decentralized finance platform, bringing financial systems expertise to blockchain infrastructure. The work spans trading components, on-c…

Build and improve the on-chain systems that support decentralized trading and financial products. You will take features from requirements and design through implementation, testi…

Lead technical delivery of AI security solutions for public-sector customers, serving as a trusted advisor from implementation through validation. The work combines customer consu…

Lead practical improvements to software quality across multiple enterprise teams, moving projects from manual-heavy testing toward dependable automation and responsible AI-assiste…

Create and support software robots that automate repetitive transportation and logistics processes in an enterprise environment. This early-career role covers the automation lifec…

Develop and operate high-performance cloud services and APIs that support systems for assessing trust and risk in voice and digital interactions. The role spans application develo…

Build and support integrations for a large SAP S/4HANA transportation and logistics platform used in defense operations. The work connects SAP applications with external systems,…

Develop and support SAP applications for transportation, logistics, financial, and business management operations. The work combines ABAP backend development with SAP S/4HANA mode…

Build and operate the distributed services that ingest real-time and recorded audio, video, and telephony metadata for downstream analytics and identity-related products. The work…

Develop and maintain ServiceNow Strategic Portfolio Management (SPM) capabilities that help an organization plan projects, manage demand and resources, and track portfolio outcome…

Help build and configure technology that supports the full lifecycle of family law matters across multiple US jurisdictions. As a practicing or former family law attorney, you’ll…

Lead complex development and configuration work across Salesforce and related applications, from technical design through implementation and support. You’ll partner with business…

Lead technical design and development of enterprise IT service management solutions on the ServiceNow platform. The work combines complex application development, process automati…

Build and support geospatial tools that help teams visualize transportation and logistics operations. Working with an experienced technical team, you will develop mapping applicat…

Own the production infrastructure that keeps AI agents and their integrations responsive, reliable, and able to handle growth. You’ll use performance measurements to guide deploym…

Build backend services that let AI agents retrieve and act on business data during customer conversations. The role focuses on reliable APIs, careful access controls, and clear fa…

Help agency partners build and adapt conversational agents for their clients, supporting both the technical implementation and the partner relationship. A central part of the work…

Take AI agents from an initial business need through deployment, working directly with customers and their existing systems. You’ll configure agents, build integrations, and add c…

Build the data pipelines and models that turn AI agent conversations into dependable analytics about sessions, requests, and outcomes. You’ll shape event definitions, transform ra…

Build and maintain integrations that let AI agents complete actions in external business systems, such as booking appointments, creating records, and sending messages. The work sp…

Build and maintain web applications and services as a senior full stack engineer, working across .NET back-end systems and TypeScript front ends. The role combines hands-on delive…

Build and maintain software in Go for a range of digital product projects, translating business needs into reliable applications. The work spans technical design, implementation,…

Work live through realistic payment-processing coding and review scenarios in a sandboxed codebase, explaining your decisions as you go. Your practical expertise will help establi…

Lead architecture and integration for high-performance enterprise web experiences in a freelance role based in Colombia. You’ll work with product, user experience, and strategy pa…

Design and guide an enterprise data architecture spanning on-premises systems and a growing cloud footprint. Working across IT, security, infrastructure, applications, and busines…

Support enterprise clients and their merchants as they adopt and operate payment and billing solutions. Serve as a senior technical contact across onboarding, integrations, escala…

Build quality practices for AI-powered applications, including language model workflows, copilots, retrieval systems, and autonomous agents. You’ll work across engineering, AI, pl…

Design and coordinate electronic data interchange (EDI) and related system integrations for customer accounts. You’ll translate business processes into integration designs, guide…

Lead the technical direction of Salesforce implementation and support projects, translating functional needs into practical solution designs. You’ll work with sales, functional, a…

A senior SAP BTP Developer is sought for a full-time development consulting role based in Colombia. The available information identifies the position and its development focus but…

This analyst leads data investigations that help identify and reduce fraud, waste, abuse, and payment errors in healthcare programs. The work combines advanced analysis, research…

Set up and maintain prototype controls used to configure small-group health plans and support automated case installation. The work combines plan setup, product data interpretatio…

Apply software development expertise and fluency in Russian to evaluate and improve AI-generated technical responses. You’ll test the model on coding tasks and engineering concept…

Evaluate and improve advanced language models by applying software engineering expertise and fluency in French. The work focuses on testing technical reasoning in realistic coding…

Review and improve AI-generated backend engineering work by applying your coding and architectural judgment. The work focuses on evaluating code for correctness, efficiency, scala…

Help protect product quality through a mix of hands-on testing and automation. You will build and maintain browser and API test coverage, improve test execution and reporting in c…

Help improve advanced language models by testing their software engineering knowledge in German. You will use coding expertise to assess technical correctness and reasoning, evalu…

Evaluate AI-generated software work across frontend and backend development, using your full stack experience to judge code quality and architectural choices. You’ll identify erro…

Use software engineering expertise and Latin American Spanish fluency to evaluate and improve AI responses to coding tasks. You’ll examine technical problem solving in Spanish, ch…

Evaluate and improve AI performance on Python software engineering problems. You will test model responses across programming concepts and practical engineering scenarios, check t…

Create and assess realistic software engineering exercises for a part-time, remote consulting engagement. The work focuses on backend and full-stack scenarios, including bug fixes…

Create and assess realistic software engineering exercises for a part-time, remote consulting engagement. The work focuses on backend and full-stack scenarios, including bug fixes…

Create and assess realistic software engineering exercises for a part-time, remote consulting engagement. The work focuses on backend and full-stack scenarios, including bug fixes…