51 senior backend developer jobs at 33 companies in Middletown, DE
1mo
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Senior Backend Engineer - Java
United States or Tampa or Boston or Atlanta or New York City or Columbus or Chicago or Philadelphia or Raleigh or Charlotte or Minneapolis or Dallas or Washington D.C. or Austin or Miami or Newark
$152k-$194k/yr RemoteFull Time
8+ YOE8+ years experience with Java/Spring Boot, JPA/Hibernate, relational databases; experience designing event-driven microservices, strong testing practices, AI-assisted development familiarity, BA/BS or equivalent.
Java 17, Java 21, Spring Boot 3.x, JPA/Hibernate 6, Postgres, Kafka, DynamoDB, Redis, OpenSearch, AWS, Docker, Kubernetes, Datadog, ArgoCD, TeamCity, Claude Code, Cursor, Codex, Model Context Protocol (MCP), GitHub, SonarQube
2mo
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Backend .NET Engineer
Philadelphia, Pennsylvania, United States
OnsiteFull Time
5+ YOE5+ years backend development with C#/.NET, REST APIs, SQL/EF Core, CI/CD, automated testing, Git, cloud (Azure preferred), spec-first workflows (OpenSpec) and experience mentoring teammates.
C#, Microsoft .NET, ASP.NET Core, ASP.NET Core Web API, SQL, Entity Framework Core, Git, Azure, OpenSpec, GitHub Spec Kit, CI/CD
1mo
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Backend Engineer, Flag Delivery
Oakland or San Francisco or New York City or Boston or Seattle or Irvine or Los Angeles or Monterey or Santa Barbara or Santa Rosa or Austin or Portland or Philadelphia or Chicago or United States
$146k-$235k/yr OnsiteFull Time
5+ YOE5+ years backend engineering experience building/operating production distributed systems; strong programming in Go/Java/Rust; production debugging, observability, on-call experience; clear AI usage in engineering work.
Go, Java, Rust
1w
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Lead Backend Engineer - Mobile APIs
Charlotte or Malvern
HybridFull Time
8+ YOE8+ years related experience, including 3+ years development and 3+ years Node.js. Undergraduate degree or equivalent experience required; graduate degree preferred.
Node.js, TypeScript, NestJS, Visual Studio Code, RESTful Services, Spring Boot, Java, AWS, CI/CD Pipeline, GitHub Actions, Git, GitHub, JIRA, Amazon ECS, AWS Fargate, Amazon EKS, AWS Lambda, Xcode, Swift, Android Studio
4w
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Sr. Backend Software Engineer (NodeJS)
United States or Minneapolis or Philadelphia or New Hartford or Austin or Champaign or Chicago
$140k-$160k/yr RemoteFull Time
8+ YOEExpertise in Node.js/Typescript and PostgreSQL, 8+ years backend experience with distributed systems, GraphQL, TypeORM, Nest.js; familiarity with Kubernetes, message brokers, AWS, Terraform.
Typescript, NodeJS, Ruby, Rails, PostgreSQL, GraphQL, TypeORM, Nest.js, RabbitMQ, RMQ, React, AWS, Terraform, Helm, Kubernetes, EKS, Microsoft Teams
1w
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Knowledge Engineer Manager - Back-end Engineer
Seattle or Milwaukee or Dallas or Columbus or Kirkland or Cincinnati or New York City or Cleveland or Oklahoma City or Austin or Albany or Chicago or St. Petersburg or Hartford or Pittsburgh or St. Louis or Miami or Sacramento or Raleigh or Minneapolis or Mountain View or Scottsdale or San Francisco or Morristown or Denver or Boston or Philadelphia or Des Moines or Overland Park or Los Angeles or Charlotte or Walnut Creek or Carmel or Houston or Arlington or Atlanta or Redmond or Bentonville or Beaverton or Nashville or Detroit or San Diego
$80k-$294k/yr HybridFull Time
5+ YOEMinimum 5 years in knowledge graph hydration, ontology mapping, graph and relational databases, vector databases, Python or Java, and REST API development; bachelor's degree or equivalent experience required.
RDF, OWL, SKOS, RDFS, SPARQL, R2RML, CSVW, SHACL, GraphDB, Stardog, Neo4j, Amazon Neptune, PostgreSQL, MySQL, SQL Server, Pinecone, Weaviate, Milvus, Qdrant, Elasticsearch, OpenSearch, Python, Java, SQL, JSON, XML, CSV, REST APIs, Apache NiFi, Airflow, Docker, Kubernetes, Helm, AWS Neptune, Azure Cosmos DB, GCP, Kafka, RabbitMQ, Git, GraphQL APIs, D3.js, Cytoscape.js, Terraform
1d
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Senior Backend DevOps Engineer (Remote Opportunity)
Philadelphia or United States
RemoteFull Time
Experience with AWS ECS, containerized microservices, CI/CD, Infrastructure as Code, AWS networking and IAM, observability, SRE, incident response, and government cloud compliance frameworks.
Amazon ECS, AWS GovCloud, AWS CLI, Infrastructure as Code, FedRAMP High, NIST 800-53, FISMA, IAM, VA Enterprise Cloud
3w
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Backend API Engineer Technical Lead II
Charlotte or Malvern
HybridFull Time
8+ YOE8+ years related experience, 3+ years Node.js, proficient in TypeScript and NestJS, experience with AWS, CI/CD, GitHub Actions, REST/Spring Boot/Java a plus; undergraduate degree or equivalent; strong communication and mentoring skills.
Node.js, Typescript, NestJS, Visual Studio Code, RESTful Services, Spring Boot, Java, CI/CD Pipeline, Github Actions, Git/GitHub, JIRA, AWS ECS Fargate, AWS EKS, AWS Lambda, XCode, SWIFT, Android Studio
3w
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Open Data Backend Engineer, (Senior Consultant, Engineering & Technical Services)
Baltimore or Alabama or California or Delaware or District of Columbia or Florida or Georgia or Maryland or New Jersey or New York or North Carolina or Pennsylvania or South Carolina or Tennessee or Texas or Virginia or West Virginia
$121k-$159k/yr RemoteFull Time
7+ YOE7+ years engineering experience with Drupal 10–11, DKAN familiarity, PHP and SQL proficiency, Git/CI-CD, automated testing, Public Trust clearance eligibility, and US residency requirements.
Drupal 11, DKAN, CKAN, Socrata, DCAT, FHIR, SQL, Drush, Docker, DDEV, docker-compose, PHPUnit, Cypress, Xdebug, Git, Varnish, Akamai CDN, GraphQL, REST
3w
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Senior Software Engineer, Backend FinPlatform
New York City or San Francisco or Salt Lake City or Los Angeles or Seattle or Austin or Washington or Philadelphia or San Diego or Chicago or Atlanta or Australia or Canada or South America
$146k-$215k/yr RemoteFull Time
6+ YOE6+ years software engineering experience, 4+ years with Java, experience with backend systems, APIs, data pipelines, AWS, and distributed teams.
Java, Spring, Gradle, JUnit, JVM, AWS, EKS, Aurora RDS, Elasticache, DynamoDB, GitHub Actions, git, DataDog, Snowflake, CDK, Terraform
3w
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Staff Software Engineer (Backend) - Billing Platform *HYBRID*
Palo Alto or Falls Church or Frisco or Washington or Baltimore or Dallas or Bethesda or Fort Worth
$110k-$230k/yr HybridFull Time
8+ YOE8+ years software development experience with large-scale systems; proficiency in Java/Kotlin/Golang, SQL/NoSQL, Kafka, Spark, Airflow, cloud and DevOps practices; strong communication and system design skills.
Java, Kotlin, Golang, SQL, NoSQL, Kafka, Spark, Airflow
6d
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Lead Software Engineer, Back End (Enterprise Platforms Technology)
McLean or New York City or Richmond or San Francisco or Philadelphia or Canada or United Kingdom or Philippines
$179k-$246k/yr OnsiteFull Time
4+ YOE1+ MgmtBachelor's degree, 4+ years of software engineering experience, and 1+ year of cloud computing experience required; leadership, programming, databases, containers, and Agile expertise preferred.
Java, Python, SQL, Node.js, Go, Scala, Docker, Kubernetes, AWS, Microsoft Azure, Google Cloud, Open Source RDBMS, NoSQL, Agile, interactive AI tooling
3w
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Senior Python Engineer, Integration
Limassol or Philadelphia or New York City or Austin or Sofia
RemoteContract
5+ YOE5+ years Python development with API and system integrations experience; strong understanding of webhooks, idempotency, observability, and scalable backend architecture.
Python, Django, Datadog, CloudWatch, Grafana
1mo
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Senior AI Engineer
United States or Wilmington
$126k-$197k/yr RemoteFull Time
8+ YOEDegree in Computer Science/Engineering, 8+ years backend development with Python and JavaScript, 2+ years production GenAI systems experience, React/TypeScript UI skills, Pydantic proficiency, strong stakeholder communication.
Python, JavaScript, React.js, TypeScript, HTML, Pydantic, PyTorch, Azure, Azure Kubernetes, Office 365, GitHub
1mo
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Nuuly Senior Software Engineer
Philadelphia, Pennsylvania, United States
OnsiteFull Time
5+ YOE5+ years software engineering experience with ~2 years senior-level responsibilities; strong JVM (Java/Kotlin/Scala) or backend skills, microservices, cloud (GCP/AWS/Azure), Docker/Kubernetes, Postgres/AlloyDB, and practical LLM/AI tool use.
Java, Kotlin, Scala, Python, Go, Node, TypeScript, JVM, Spring, Google Cloud Platform (GCP), AWS, Azure, Docker, Kubernetes, Postgres, AlloyDB, Kafka, Spark, Storm, RESTful APIs, ChatGPT, Claude, Cursor, Windsurf, Copilot, MCP
1w
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Senior Software Engineer
Berwyn, Pennsylvania, United States
HybridFull Time
7+ YOE7+ years backend engineering with Java/Python, 2+ years hands-on AI/ML, experience designing distributed transactional systems in regulated fintech, security/observability knowledge, and production incident handling.
Java, Python, Spring Boot, SQL, Kafka, Kubernetes, Docker, LangGraph, RAG, Vector Stores
4w
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Senior Software Engineer
Baltimore, Maryland, United States
$140k-$160k/yr RemoteFull Time
5+ YOE5+ years software engineering experience, ownership of features from design to production, deep Ruby on Rails backend expertise, relational DB design, strong communication; React and Flutter experience preferred.
Ruby on Rails, React, Flutter, AWS, ECS, RDS, S3
4w
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Senior Software Engineer
Baltimore, Maryland, United States
$140k-$160k/yr RemoteFull Time
5+ YOE5+ years software engineering experience; strong Ruby on Rails backend skills; product-minded; experience with React and Flutter, relational databases, security and reliability (HIPAA/SOC 2); strong communication.
Ruby on Rails, React, Flutter, AWS, ECS, RDS, S3
2mo
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Software Engineer 2
Annapolis Junction, Maryland, United States
HybridFull Time
14+ YOESenior backend developer with TS/SCI CI Poly clearance; Java/Spring/Maven; 14+ years experience; BS in CS or related field; NoSQL/Big Data and CI tools
Java, Spring Framework, Maven, MongoDB, ElasticSearch, Jenkins, Git, PostgreSQL, Python, Hadoop, Hive, Pig, MapReduce, NoSQL
2mo
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Sr. Software Engineer
Wayne or Naperville
$120k-$135k/yr HybridFull Time
5+ YOE5–7 years backend engineering or intelligent systems with production impact; strong Python, CI/CD, and system design; experience with ML model APIs and cloud inference; familiarity with vector databases and retrieval systems.
Python, CI/CD, AWS Bedrock, Azure OpenAI, Google Vertex AI, PyTorch, Hugging Face Transformers, vLLM, FAISS, Pinecone, OpenSearch/KNN, LangChain, LlamaIndex, MLflow, Weights & Biases, Prometheus
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