Lead Software Engineer – Full Stack | Node.js, TypeScript, React | B2B SaaS

📍 Remote – India💰 ₹25–50 LPA total CTC, depending on experience and scope🕒 Full-timeNode.js | TypeScript | React | Full Stack Engineering | Multi-Tenant SaaS | Enterprise SaaS | Technical LeadershipOwn a major product area. Lead the engineering. Stay deeply involved in the code.Script Assist is looking for a hands-on Lead Software Engineer with deep production experience in Node.js, TypeScript and React to take technical ownership of a substantial part of our platform.We are particularly interested in engineers who have built and evolved large, complex, multi-tenant B2B SaaS products with:Multiple interconnected product modulesCustomer-specific configurationsComplex workflows and state transitionsRoles and permissionsLarge integration surfacesAPIs and webhooksSignificant production dataDifferent customer behaviours and requirementsYears of accumulated product complexityThis is not simply a senior developer position.We need someone who can own an area technically, make important engineering decisions, maintain very high standards across the code written by others, mentor engineers and remain capable of personally solving the hardest technical problems.You may currently be a:Lead Software EngineerLead Full Stack EngineerTechnical LeadTech LeadSenior Software EngineerSenior Full Stack EngineerHands-on Staff EngineerFull Stack Technical LeadYour current title matters less than the level at which you already operate.About Script AssistScript Assist is a UK healthcare technology company providing the software and operating infrastructure behind complex private clinical and pharmacy services.Our platform connects:ClinicsPharmaciesPrescribersPatientsOperational teamsExternal technology providersand supports tens of thousands of structured clinical and pharmacy transactions every month.The platform includes complex functionality across:Clinical workflowsPrescribingMedication managementPharmacy operationsInventoryDispensingPaymentsSubscriptionsFulfilmentCommunicationsReportingPermissionsIntegrationsCustomer-specific configurationOperational automationHealthcare experience is not required.What matters is that you have already built sophisticated software products where many features, workflows, integrations and customer configurations interact with each other.The Engineering ProblemScript Assist is not a simple CRUD application.Different customers may use the same underlying platform in different ways.A new feature can interact with:Existing workflowsDifferent user rolesTenant-specific configurationExternal integrationsPayment statesOperational processesExisting customer dataHistorical product decisionsWe need engineers who understand how to extend a mature shared product without creating an unmaintainable collection of exceptions.You should be comfortable thinking about questions such as:How should customer-specific behaviour be represented?Should this be configuration or code?How should workflows be versioned?What happens to processes already in progress?How do we prevent duplicate actions when events retry?How do we maintain data integrity across several systems?How do we change one module without breaking another?How do we make increasingly complicated software easier—not harder—to maintain?🔧 What you will ownTechnical ownershipYou will take responsibility for a substantial product domain.That will include:Technical designBackend servicesData modelsReact applicationsAPIsIntegrationsTesting strategyDeploymentProduction behaviourTechnical debtReliabilityYou should become the person who can say:“I understand this area end-to-end and I am responsible for its technical quality.”Hands-on engineeringYou will remain deeply involved in implementation.You will:Write production Node.js / TypeScript backend codeBuild and review React / TypeScript applicationsDesign APIs and service contractsWork directly with databasesDebug difficult production behaviourRefactor problematic areasImplement technically difficult functionalityReview and improve existing architectureThis is not an architecture-only role.Technical leadershipYou will:Lead design discussionsBreak large engineering problems into sensible piecesReview important pull requestsMaintain high coding standardsChallenge poor abstractionsIdentify hidden dependenciesMentor engineersImprove testing and release disciplineEstablish reusable patternsHelp engineers make better technical decisionsThe goal is not for you to personally write every difficult piece of code.The goal is for the engineering around you to become better because you are there.The SaaS experience we care aboutWe want engineers who have genuinely worked on shared multi-tenant software products.Relevant experience may include:Multi-tenancyTenant isolationTenant-aware data modelsCustomer configurationEntitlementsFeature flagsOrganisation structuresMulti-company / multi-entity architectureComplex workflowsWorkflow enginesRules enginesApproval processesState machinesStatus transitionsLong-running processesWorkflow configurationException handlingPermissions and governanceRBACRoles and permissionsOrganisational hierarchiesAudit trailsAccess controlIntegrationsREST APIsGraphQLWebhooksExternal servicesBackground jobsMessage queuesEvent-driven systemsThird-party integration failuresProduction complexityIdempotencyRetriesConcurrencyReconciliationTransactionsData migrationsBackward compatibilityIncident investigationObservabilitySafe releasesYou do not need every item above.You do need evidence that you have already worked inside a genuinely complex shared software product.Essential technical experienceYou should have substantial recent experience with:Node.jsTypeScriptReact / React.jsBackend service developmentAPI designDatabase designProduction softwareAutomated testingGitCI/CDDockerCloud-deployed systemsExperience with the following is particularly useful:NestJSExpressFastifyPostgreSQLMongoDBRedisGraphQLKafkaRabbitMQSQS or other queuesKubernetesAWS / Azure / GCPObservability and monitoringWe do not require one particular database or cloud provider.ImportantYour Node.js experience must include real backend business logic and production services.Node used only for:Front-end toolingSSRBuild systemsVery thin BFF layerswill not be enough by itself.Relevant backgroundsWe are particularly interested in engineers from mature B2B SaaS and enterprise software product companies.Relevant environments may include teams at:FreshworksOkta / Auth0Blue Yonder / JDA SoftwareLeadSquaredDiligentPostmanOther enterprise SaaS, workflow, CRM, identity, automation or operational-software companiesThese companies are examples, not requirements.We care about what you personally built and owned, not simply the logo on your CV.How we expect you to leadWe want somebody who:Is obsessive about code qualityReviews other engineers’ work carefullyUnderstands architectural consequencesSpots complexity before it becomes technical debtCan challenge Product constructivelyMakes pragmatic trade-offsWrites difficult code when necessaryHelps others solve difficult problemsDoes not create dependency on themselvesTakes responsibility for production outcomesStrong written and spoken English is important.ExperienceWe expect most strong candidates will have approximately 8–14+ years of software engineering experience.But years alone are not the deciding factor.An exceptional engineer with fewer years but substantial ownership can be more interesting than someone with a longer but narrower career.📈 Why join Script Assist?This is an opportunity to move from being one senior engineer inside a very large organisation to owning a meaningful part of an entire product platform.You will have genuine influence over:ArchitectureProduct behaviourCode qualityEngineering standardsProduction reliabilityTechnical strategyHow other engineers workYou will remain hands-on.But your impact should increasingly come not only from the code you write yourself, but from the quality of the entire area you lead.