Electrical connectors, electrical modules, and systems are provided. In one aspect, an electrical connector includes a housing defining a side surface, an electrical conductor supported by the housing and including an engagement portion proximate the side surface of the housing. The engagement portion is adapted to engage another electrical conductor of another electrical connector. The connector also includes a magnet supported by the housing proximate the side surface of the housing, a projection extending from the side surface of the housing, and a receptacle defined in the side surface of the housing. In other aspects, an electrical module includes at least one of these electrical connectors. In further aspects, a system includes a plurality of these modules and the modules are selectively couplable together.

Technical solutions are directed to creation and deployment of multi-stage test problems. A processor can provide, to a client, a first data structure for a first stage of a multi-stage test problem including a description for generation of a client solution for the first stage and a test case to evaluate the client solution. The processor can receive, from the client, a client data structure comprising the client solution including a client computer code generated at the client for the first stage. The processor can determine, by evaluating the client solution using an input value and an output value of the test case, that the output of the client solution satisfies a validity condition of the output value. The processor can provide, to the client, based on satisfying the validity condition, a second data structures for a second stage of the multi-stage test problem.

A versatile Logic teaching system comprising a plurality of interchangeable functional tile units representing binary values representing various logic functions and connector tiles linking the functional tile units. In use, functional tile units and connector tiles can be arranged to create logical circuit pathways representative of real-world scenarios. Construction of logical circuit pathways can follow one or more rules and a scoring system to engage users.

Technical solutions are directed to creation and deployment of multi-stage test problems. A processor can provide, to a client, a first data structure for a first stage of a multi-stage test problem including a description for generation of a client solution for the first stage and a test case to evaluate the client solution. The processor can receive, from the client, a client data structure comprising the client solution including a client computer code generated at the client for the first stage. The processor can determine, by evaluating the client solution using an input value and an output value of the test case, that the output of the client solution satisfies a validity condition of the output value. The processor can provide, to the client, based on satisfying the validity condition, a second data structures for a second stage of the multi-stage test problem.

Technical solutions are directed to generating annotated timelines of a client solution generation. A processor can identify computer code entries for a test problem client solution created at a client. Each of the entries can have a portion of the computer code associated with a timestamp. The processor can apply a filter to the entries to select a subset of entries using a difference between a first timestamp of each entry and a second timestamp of a preceding entry satisfying a time selection criteria, or a difference between a first portion of the computer code of the entry and a second portion of the computer code of a preceding entry satisfying a code selection criteria. The processor can generate a timeline of events indicating actions at the client device during creation of the computer code for the client solution and provide the timeline for display.