It’s not a good idea to check an interface for nil. Try the following code: type user interface{} type staff struct{} func compareNil() { var generic user generic = nil // works as expected fmt.Printf("value=%v type=%T (generic==nil)=%v\n", generic, generic, generic == nil) generic = (*staff)(nil) //…

A short read — https://shopify.engineering/mobius-shopify-unified-edge What is the Problem? The traffic could be ingress from multiple sources. Edge could support a few types of applications only. It was hard to onboard a new service to the edge. Observability of overall traffic was missing or incomplete. What’s an Edge? The edge is a boundary…

What is Strategy Pattern — The strategy is a behavior pattern. It fits where multiple choices for an interface are available and the design would allow switching them dynamically. Conditions A set of choices with similarities in the interface Dynamic update of a choice Example A cache with evictions Multiple eviction algorithms A cache could switch to…

The answer is Maglev. Maglev is a L3/L4 software load balancer. A load balancer such as Nginx, and HAProxy distributes requests among multiple backend services. Goals It should allow seamless scalability so a set of load-balancers can be added/removed and the user does not notice any connection drop. A set of…

migrate Database migrations tool is written in Go. Use as CLI or import as a library. Migrate reads migrations from sources and applies them in the correct order to a database. The migration tool uses a schema_migrations table. One table exists for one DB. mysql> select * from schema_migrations; +---------+-------+ | version |…

PROBLEM — json: cannot unmarshal object into Go struct field CODE package main import ( "encoding/json" "fmt" ) // DTO object type mould struct { Particle tiny } type tiny interface { GetName() string } // Implement the interface type speck struct { Name string `json:"name"` } func (s *speck) GetName() string {…